"The goal is to expose the artist." Wesley Pentz is on the phone from Hawaii, explaining how he publicizes up-and-coming hip-hop talent. "It's basically putting promotion and marketing in your own hands," he explains. Contrary to what you may think, Pentz is not a record executive; he's a DJ with a passion for making mix tapes -- not the romantic type you made for your college girlfriend, but the compilation cassettes (and CDs) created in bedroom studios, copied in bulk and found for sale on the streets of urban centers like New York, London and Miami.

For Pentz, better known on the club circuit as Diplo, taking a business approach to his art is nothing new. He has learned to combine his mixing skills with media savvy, turning a career spinning in clubs into a globe-trotting, genre-hopping exploration of sound.

Consider "Piracy Funds Terrorism," his recent collaboration with Maya Arulpragasam, a Sri Lankan Tamil emigre to London whose work encompasses dance hall MCing, electro and hip-hop. Arulpragasam, known professionally as M.I.A., chirps over rhythms that Diplo has liberally borrowed from old-school hip-hop, first-generation MTV pop and baile funk, the jittery, bass-heavy party music born in the ghettos of Brazil.